Simultaneous synthesis and integration of nanoscale silicon by three-photon laser direct writing

Abstract

Typical fabrication processes of compact silicon quantum dot (Si QD) devices or components entail several synthesis, processing and stabilization steps, leading to manufacture and cost inefficiency. Here we report a single step strategy through which nanoscale architectures based on Si QDs can be simultaneously synthesized and integrated in designated positions by using a femtosecond laser (532 nm wavelength and 200 fs pulse duration) direct writing technique. The extreme environments of a femtosecond laser focal spot can result in millisecond synthesis and integration of Si architectures stacked by Si QDs with a unique crystal structure (central hexagonal). This approach involves a three-photon absorption process that can obtain nanoscale Si architecture units with a narrow line width of 450 nm. These Si architectures exhibited bright luminescence peaked at 712 nm. Our strategy can fabricate Si micro/nano-architectures to tightly attach to a designated position in one step, which demonstrates great potential for fabricating active layers of integrated circuit components or other compact devices based on Si QDs.